A comprehensive analysis of recruitment and transactivation potential of K-Rta and K-bZIP during reactivation of Kaposi's sarcoma-associated herpesvirus

Virology. 2009 Apr 25;387(1):76-88. doi: 10.1016/j.virol.2009.02.016. Epub 2009 Mar 9.

Abstract

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma. K-Rta and K-bZIP are two major viral transcription factors that control reactivation of this virus. Here we report a genome-wide analysis of transcriptional capacity by evaluation of a comprehensive library of 83 putative KSHV promoters. In reporter assays, 34 viral promoters were activated by K-Rta, whereas K-bZIP activated 21 promoters. When K-Rta and K-bZIP were combined, 3 K-Rta responsive promoters were repressed by K-bZIP. The occupancy of K-Rta and K-bZIP across KSHV promoters was analyzed by chromatin immunoprecipitation with a viral promoter-chip in BCBL-1 cells. In addition, acetylation of local histones was examined to determine accessibility of promoters during latency and reactivation. Finally, 10 promoters were selected to study the dynamics of transcription factor recruitment. This study provides a comprehensive overview of the responsiveness of KSHV promoters to K-Rta and K-bZIP, and describes key chromatin changes during viral reactivation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic-Leucine Zipper Transcription Factors
  • Cell Line
  • DNA, Viral / genetics
  • Gene Expression Regulation, Viral
  • Herpesvirus 8, Human / genetics
  • Herpesvirus 8, Human / physiology*
  • Humans
  • Immediate-Early Proteins / metabolism*
  • Promoter Regions, Genetic / physiology*
  • Trans-Activators / chemistry
  • Trans-Activators / metabolism
  • Trans-Activators / physiology*
  • Transcriptional Activation
  • Virus Activation*
  • Virus Replication

Substances

  • Basic-Leucine Zipper Transcription Factors
  • DNA, Viral
  • Immediate-Early Proteins
  • Trans-Activators